(1) Field of the Invention
The present invention relates to a flow-control system for a container for dispensing a liquid, and more particularly to a flow-control system for dispensing a measured amount of a liquid at a controlled rate.
(2) Description of the Related Art
Various dispensers for dispensing a liquid are known in the art. For example, various containers may be employed for dispensing liquids such as soap, eye wash, shampoo, ear wash, mouthwash, and medicine. These containers generally employ a flexible plastic reservoir portion for holding the liquid that can be squeezed to apply pressure to the liquid contained therein for transporting the liquid toward a dispensing opening or outlet. Typically, these devices will employ a large reservoir for holding liquid that is in communication with a single outlet such as a hole. When pressure is applied to the liquid-holding reservoir, the liquid is then expended from the container through the opening.
Often, overexertion of pressure on the reservoir will cause the liquid to be dispensed at a rate that is not suitable for the use of the container. For example, when the container holds eye wash or ear wash, an over-application of pressure to the reservoir will result in a hard stream of liquid that could result in agitation to, and perhaps injury to, the eye, nasal septum, or eardrum.
In addition, it has long been recognized that the requirements for administering liquids in accurate amounts, such as is required for medicines, drugs, vitamins, and the like, are different than for the consumption of foods. This is particularly true where the subject is a child or infant. In the case of medicines, the amount of the liquid must be carefully controlled, and care must be taken to insure that the entire dose is successfully administered. When the subject is an infant, consumption may not be voluntary, and spillage is a danger. Moreover, when an infant is to receive the liquid, great care must be taken to avoid over-insertion of a dosing device into the mouth and throat, thereby causing choking.
Furthermore, it is important to avoid the discharge of liquid into the throat, of a child or infant at a rate that will startle the child, or result in choking or involuntary gagging. This potential exists when pressure is misapplied to the reservoir holding the liquid. On the other hand, application of a liquid medicine into the front of the mouth of a child will often result in loss of some or all of the medicine by spitting or drooling.
In response to these requirements, various devices have been described that are designed to address one or more of the particular requirements. For example, dispensing devices having open, spoon-like bowls in which a liquid is offered are described in U.S. Pat. Nos. 2,795,043, 4,888,188, 6,264,074, 5,154,318, 5,975,305, 4,841,637, 3,133,679, 3,473,221, 4,192,360, 4,830,222, 6,347,727, 3,946,652, D496,833, 3,116,152, among others. Such devices, however, in most cases, require the subject receiving the contents to voluntarily accept and remove the contents of the bowl when presented.
Spoons that provide for dispensing a liquid at or near the distal end of the bowl are described in U.S. Pat. Nos. 2,688,243, 5,038,974, 5,038,476, 201,369, D34,314, D52,688, D24,197 and D368,209. Many of these devices appear to depend upon either gravity, or an action by the recipient, to deliver the contents of the device.
Feeding devices or injecting devices having multiple parts, and which are designed for refilling and reuse, are described in U.S. Pat. Nos. 4,880,409, 5,556,008, 878,524, 1,661,595, 3,090,071, 3,410,457, 4,182,002, 5,062,550, among others.
Other pre-filled disposable containers are described in U.S. Pat. No 6,357,626.
Systems and designs that may control or limit the flow rate of liquids from certain containers are described in U.S. Pat. Nos. 4,087,022, 878,524, 1,661,595, 3,410,457, 4,182,002, 5,062,550, 5,154,318, 6,357,450, 2,293,922, 3,133,679, 4,192,360, 6,347,727, R24,251, and 4,890,744.
Yet, with the advances of the prior art, several problems remain to be overcome. It would be beneficial if a flow control mechanism could regulate the flow of liquid through the dispensing outlet so that the liquid contents could be delivered into the back of the mouth of the user, when the device is used to deliver a liquid orally, to minimize loss of the liquid by spitting or drooling, but yet at a velocity that is sufficiently low to avoid triggering a gagging reflex.
In addition, for certain uses, it would be useful to provide a dispensing container that did not have multiple parts and that could be made simply and inexpensively. It would also be useful if such dispensing container could be disposed after a single use. It would be useful if such a container could be designed to avoid requiring the user or another person to fill the container and/or measure the amount of liquid to be dosed, thereby improving accuracy, avoiding mistakes, and reducing waste. It would additionally be useful if such a container protected the integrity of the contents during packaging, transporting, selling and storage.
It would be particularly useful if the dispensing containers could be utilized in a safe manner that does not have the potential for aggravating the area to which the liquid is being applied. Furthermore, it would be useful if such dispensing container could be safely used when dispensing oral, ear, nasal, or eye medicaments, such as with infants. Controlling flow of the liquid from the container as well as avoiding over-insertion of the container into the mouth of an infant and thereby protecting against choking would likely result in a safe application of the liquid to an infant.